30-Second Psychology: The 50 Most Thought-provoking Psychology Theories, Each Explained in Half a Minute - Christian Jarrett 2011
Experts and lay people alike used to think that groups make more conservative decisions than individuals. The mistaken reasoning was that groups come to decisions that reflect the average position of all group members, thereby diluting extremist views. A groundbreaking study by James Stoner in 1961, since replicated hundreds of times, showed that in fact groups make more polarized decisions than individuals. Whether it be in relation to financial risk-taking or political attitudes, group discussion accentuates any initial bias held by group members. In the early 1970s, Yale University psychologist Irving Janis argued that certain conditions can lead to a particularly extreme form of group polarization called ’groupthink’, in which a dangerous illusion of consensus takes over. The preconditions for groupthink include members being close-knit and like-minded, a group leader who makes his or her own position known, and the group being shut off from other influences and opinions. Janis argued that groupthink was responsible for the catastrophic decision making that led to the Bay of Pigs Invasion and the United States’ failure to anticipate Japan’s attack on Pearl Harbor.
Groups of like-minded individuals shut off from outside influence can end up ignoring dissent and making some truly disastrous decisions.
Since Janis’ seminal work, groupthink has been blamed for multiple catastrophes, including the Challenger Space Shuttle disaster and, more recently, the intelligence community’s mistaken belief, prior to the Iraq War, that Saddam Hussein had stockpiles of Weapons of Mass Destruction. ’Groupthink caused the [intelligence] community to interpret ambiguous evidence such as the procurement of dual use technology, as conclusive evidence,’ Pat Roberts, then Chairman of the Senate Intelligence Committee, told the press in 2004.
WASON’S CONFIRMATION BIAS
THE BYSTANDER EFFECT
FOLLOW THE LEADER
History shows that groups are capable of making terrible decisions, especially when they are cut off from dissenting opinions.